In our patient, the BWS diagnosis was based on the typical clinical findings as well as additional features such as wide neck, micro-clinodactyly of fourth and fifth fingers and toes, skin syndactyly, skin pigmentation abnormalities and 46,XX ovotesticular disorder. To the best of our knowledge, this is the first BWS patient found to have a coexisting ovotesticular disorder. Because gonadal differentiation involves a very complex genetic program at different embryonic stages, the occurrence of any disorder of sexual development (DSD) is a clinical challenge. The ovotesticular disorder is a rare DSD and the predominant karyotype (70% of cases) in these patients is 46,XX followed by chimerism XX/XY in about 20% [
9]. Testicular differentiation is accounted for by the presence of the master
SRY gene in only 2% to 12% of cases, and remains unexplained in the remainder of cases. However, it has been suggested that mutations or deregulation of other genes involved in gonadal development in a 46,XX embryo can produce ambiguous genitalia [
10,
11]. One marker of mammalian testis development is the size increase of rudimentary XY gonad, which is determined by the presence of
SRY. The male-size increase is the result of coelomic cell proliferation after 24 hours of
SRY gene expression, and originates in two stages. The first stage is the proliferation of SF1-positive cells, which will eventually give rise to the Sertoli cells. The second stage is the proliferation of SF1-negative cells. It has been postulated that this cell proliferation alters the transcriptional accessibility of the
HOX gene clusters, thereby controlling the timing of the expression of specific genes and consequent cell differentiation [
12]. In the present patient we did not find any Y-chromosome sequences by FISH; however, we cannot rule out the possibility of a cryptic mutation or a small Y-bearing clone. Moreover, our patient also shares features with the Denys–Drash syndrome (Online Mendelian Inheritance in Man [OMIM] #194080) mapped in 11p13 whose distinctive features are Wilms’ tumor and a DSD similar to the 46,XX ovotesticular disorder. The implicated gene in Denys–Drash syndrome is
WT1 which encodes for a zinc finger transcription factor that is expressed very early in the urogenital ridge and plays a crucial role in gonadal differentiation. A concurrent mutation in the
WT1 gene may explain the DSD in our patient. Recent reports in mice indicate the imprinted genes network (IGN) regulates the gene expression through modulation of the imprinting pattern at different embryogenesis stages [
13,
14]. For instance, the transcription factor
ZAC1, one of the major IGN genes, especially modulates the expression of
H19 and/or
IGF2 genes. Accordingly, we speculate that in our patient a change in the methylation pattern of
ZAC1 modifies the expression of
H19 and/or
IGF2 and gives rise to BWS phenotype, and perhaps even to the brachydactyly, because such a gene is highly expressed in chondrogenic tissue [
15]. Because
ZAC1 also regulates
SOX11, whose possible function is in gonadal development [
16], the patient’s 46,XX ovotesticular disorder could result from an impaired IGN, although a random association cannot be excluded. In order to clarify the presence of these two complex pathologies (BWS and 46,XX ovotesticular disorder) in our patient is important to carry out future molecular analysis.